Wireless networks implement protocols for medium access control (MAC). These MAC protocols handle, for example, contention between multiple devices requesting access to the network medium. For example, when two computers are connected to the same wireless network on a single channel and in transmission range of each other, generally only one computer can communicate at a time on the channel. A MAC protocol operates on both of the computers to determine when the computer can transmit data on the wireless network. When both computers attempt to transmit at the same time, their data is lost and the MAC protocol determines how to handle the contentious transmission.
Conventionally, the IEEE 802.11 standard has been used as a MAC protocol on computers. The IEEE 802.11 standard is a contention-based MAC protocol, such that no fixed assignments of time on the network are generally assigned to computers. However, contention-based MAC protocols such as IEEE 802.11 suffer from probabilistic delay guarantees, severe short-term unfairness, and poor performance at high loads. One reason for selecting such a contention-based MAC protocol, despite poor performance, is the ability of the MAC protocol to adapt to changing topology in the wireless network.
One conventional solution for implementing scheduling algorithms in networks with changing load and topology is to alternate a contention phase with a scheduled phase in a hybrid solution. In the contention phase, nodes exchange topology information used to compute a conflict-free schedule that is followed in the subsequent scheduled phase. However, changes in topology and load do not always align with the phases of the algorithm resulting in a schedule that often lags behind the network state.